The present invention relates to a pneumatic tire, more particularly to a rib-based tread pattern capable of improving the drainage performance while maintaining the uneven wear resistance and noise performance of the tire.
In general, a pneumatic tire is provided in the tread portion with circumferentially continuously extending main grooves to remove water existing between the tread and road surface toward the outside of the ground contacting patch of the tire.
In order to improve the drainage performance, if wide straight main grooves are provided in the tread portion, so called air column resonance which deteriorates the noise performance of the tire is likely to occur during running. In addition, since the ground contacting area is decreased by the wide main grooves, the rigidity of the tread portion is decreased, and the uneven wear resistance of the tread portion tends to deteriorate.